Disease relevance of tsh

• To determine whether integrons may play a role in avian pathogenic Escherichia coli, isolates of extra-intestinal (n = 27) and intestinal (n = 40) E. coli from dead chicks and turkey poults were analysed for the presence of class 1 integrons and of the virulence-associated genes iss, tsh and colV [1].
• The tsh determinant was identified in 63% of our clinical UPEC strain isolates (n = 87) and in 33% of fecal strains (n = 27), whereas pic was present in 31% of the pyelonephritis (n = 67) and 7% of the fecal strains [2].
• DNA sequences flanking the tsh gene of strain chi7122 include complete and partial insertion sequences and phage-related DNA sequences, some of which were also found on virulence plasmids and pathogenicity islands present in various E. coli pathotypes and other pathogenic members of the Enterobacteriaceae [3].
• The primary sequence of PssA is highly related to a family of autonomously transported putative virulence factors from different Gram-negative pathogens, which includes the Tsh protein of an avian-pathogenic E. coli strain, the SepA protein from Shigella flexneri and the EspC protein from enteropathogenic E. coli [4].
• Extensive similarities were detected between the sequence of the first 500 residues of mature SepA and the N-terminal region of IgA1 proteases from Neisseria gonorrhoeae and Haemophilus influenzae, the Tsh haemagglutinin of an avian pathogenic Escherichia coli, and the Hap protein involved in adhesion and penetration of H. influenzae [5].

High impact information on tsh

• In contrast, the presence of tsh was not necessary for high levels of virulence [6].
• Here we establish the size of pVM01 to be approximately 160 kb and show that the putative virulence genes iss (increased serum survival) and tsh (temperature-sensitive hemagglutinin) and the aerobactin operon are on the plasmid [6].
• Autotransporter genes pic and tsh are associated with Escherichia coli strains that cause acute pyelonephritis and are expressed during urinary tract infection [2].
• We have identified two chromosomal open reading frames in uropathogenic Escherichia coli (UPEC) strain CFT073 which are highly homologous to serine protease autotransporters Pic and Tsh [2].
• Conjugation and hybridization experiments revealed that the tsh gene is located on a ColV-type plasmid in many of the APEC strains studied, including strain chi7122, near the colicin V genes in most of these strains [3].

Chemical compound and disease context of tsh

• Hybridization studies have revealed that this plasmid contains sequences with homology to tsh, a gene associated with virulence of avian E coli; intI 1, a gene encoding the integrase of Class 1 integrons; and certain genes of the aerobactin- and CoIV-encoding operons [7].

Biological context of tsh

• All extra-intestinal strains had the colV, iss and tsh genes, but none of these genes were cotransferred with the 1.0 kb integron when conjugal transferability was tested [1].
• Insertional mutagenesis of the chromosomal tsh gene in chi 7122 had no effect on hemagglutination titers [8].
• A definite tendency has been established, indicating a decreased rate of oxygen consumption and dehydrogenase activity of the hybrids, compared to the respiratory activity of the virulent recipient strains tsh. flexneri in all substrates used [9].
• This gene confers on E. coli K-12 a temperature-sensitive hemagglutination phenotype that is best expressed when cells are grown at 26 degrees C, and we have designated this gene tsh and the deduced gene product Tsh [8].

Anatomical context of tsh

• In this report we show that E. coli K-12 containing the recombinant tsh gene produced two proteins, a 106-kDa extracellular protein and a 33-kDa outer membrane protein, and was also able to agglutinate chicken erythrocytes [10].
• Conjugation with a nalidixic acid (Na) resistant K-12 recipient strain (MS101) showed that the 98MDa plasmid did not transfer, whereas transfer of the 60MDa plasmid resulted in concomitant transfer of adhesion to Hep-2 and tracheal epithelial cells, production of the colicins Ia, E1, E3, and K, and the tsh-related DNA sequence [11].

Associations of tsh with chemical compounds

• Clinical isolates and 194 fecal isolates with biochemical phenotypes or minimum inhibitory concentrations for gentamicin and sulfamethoxazole similar to clinical isolates were tested for somatic antigens and the potential virulence genes hylE, iss, tsh, and K1 [12].

Analytical, diagnostic and therapeutic context of tsh

• Most isolates were PCR positive for the increased serum survival gene (iss; 97%) and the temperature-sensitive hemagglutinin gene (tsh; 93%) [13].

References